By Dr. Mercola
Vegetables offer a wide range of health benefits, but some seem to have greater potential to ward off disease than others. Broccoli falls into this category, having been widely studied for its many health effects.
Research shows this cruciferous veggie (in the same family as Brussels sprouts, cabbage, cauliflower and more) may reduce your risk for many common diseases, including but not limited to:
- High blood pressure and heart disease
- Kidney disease
Broccoli Contains Many Health Boosting Compounds
When you eat broccoli, you're getting dozens, maybe even hundreds, of super-nutrients that support optimal, body-wide health. This includes but is not limited to:
• Fiber, which helps nourish your gut microbiome and strengthen your immune function.
• Sulforaphane, a naturally occurring organic sulfur compound shown to have potent anti-cancer activity.
Studies have shown sulforaphane causes apoptosis (programmed cell death) in colon,1 prostate,2 breast3 and tobacco-induced lung cancer4 cells. Three servings of broccoli per week may reduce your risk of prostate cancer by more than 60 percent.5
Sulforaphane encourages production of enzymes that protect your blood vessels, and reduces the number of molecules that cause cell damage — known as reactive oxygen species (ROS) — by as much as 73 percent.6
Interestingly, sulforaphane is both an immune stimulant and an anti-inflammatory.7
Sulforaphane also helps raise testosterone levels, inhibits the retention of body fat, helps detox carcinogens,8 blocks certain enzymes linked to joint destruction9 and helps protect your muscles against exercise-induced damage.10
Please note that frozen broccoli has diminished ability to produce sulforaphane as the enzyme myrosinase,11 which converts glucoraphanin to sulforaphane, is quickly destroyed during the blanching process.12
• Glucoraphanin, a glucosinolate precursor of sulforaphane that also influences the process of carcinogenesis and mutagenesis.13,14 Compared to mature broccoli, broccoli sprouts can contain up to 20 times more glucoraphanin.
• Phenolic compounds, including flavonoids and phenolic acids, which have a potent ability to eliminate damaging free radicals and quell inflammation,15,16,17 resulting in a lower risk for diseases such as asthma, type 2 diabetes and heart disease.18
One of the ways phenolic compounds slow the encroachment of disease is by defending against infection, most dramatically by zapping ROS linked to atherosclerosis and neurodegenerative diseases such as Parkinson's and Alzheimer's.
• Diindolylmethane (DIM). Your body produces DIM when it breaks down cruciferous vegetables. Like many other broccoli compounds, DIM has shown multiple potential benefits, including boosting your immune system and helping to prevent or treat cancer.19,20
Broccoli Reduces Risk of Fatty Liver and Liver Cancer
Non-alcoholic fatty liver disease (NAFLD), which affects up to 25 percent of Americans,21 including children, is defined as an excessive accumulation of fats in your liver in the absence of significant alcohol consumption.
The overconsumption of net carbs, especially fructose in soda and juices, is strongly associated with NAFLD which, if left untreated, can raise your risk of hepatocellular carcinoma (liver cancer).
The reason for this is because, contrary to other sugars, nearly all of the fructose you consume gets shuttled to your liver, and — if you consume high amounts of it — it taxes and damages your liver in the same way alcohol and other toxins do.
As noted in one 2015 study: "Ingested carbohydrates are … more likely to directly contribute to NAFLD than dietary fat intake."22
The fat-forming and pro-inflammatory effects of fructose appear to be due to transient ATP (the chemical storage form of energy) depletion, according to the study. This in turn leads to uric acid formation, which at excessively high levels acts as a pro-oxidant inside your cells.
According to an animal study published earlier this year, long-term consumption of broccoli may reduce your chances of developing fatty liver and liver cancer caused by the standard American diet by lowering triglyceride levels in your liver.23,24
The Superior Benefits of Broccoli Sprouts
An excellent alternative if you don't like the taste (or smell) of broccoli is to eat broccoli sprouts. Sprouted broccoli seeds are also far more potent, nutritionally speaking, than mature broccoli. As a result, you don't need to eat nearly as much to reap the clinical benefits from key therapeutic compounds like sulforaphane.
Research shows that even small quantities of broccoli sprout extract have the power to markedly reduce the size of rat mammary tumors induced by chemical carcinogens. As noted by researchers at Johns Hopkins University:25,26
"Three-day-old broccoli sprouts consistently contain 20 to 50 times the amount of chemoprotective compounds found in mature broccoli heads, and may offer a simple, dietary means of chemically reducing cancer risk."
Besides the advantages already listed, broccoli sprouts deliver essential fatty acids and fiber, and boost the bioavailability of minerals and protein from other foods you eat. Another major benefit is that you don't have to cook them.
They are eaten raw, usually as an addition to salad, making them a super-healthy convenience food. Best of all, you can easily and inexpensively grow broccoli sprouts at home.
Lightly Steam Your Broccoli to Boost Sulforaphane Content
When you eat raw mature broccoli, you only get about 12 percent of the total sulforaphane content theoretically available based on the parent compound. You can increase this amount and really maximize the cancer-fighting power of broccoli by preparing it properly.
The featured video interview with Elizabeth Jeffery, Ph.D., a researcher and professor in the Department of Food Science and Human Nutrition at the University of Illinois, delves into this research,27 which shows that steaming your broccoli for three to four minutes is ideal. Do not go past five minutes.
Steaming your broccoli spears for three to four minutes will optimize the sulforaphane content by eliminating epithiospecifier protein — a heat-sensitive sulfur-grabbing protein that inactivates sulforaphane — while still retaining the enzyme myrosinase, which converts glucoraphanin to sulforaphane. Without it, you cannot get any sulforaphane.
Boiling or microwaving your broccoli past the one-minute mark is NOT recommended, as it will destroy a majority of the myrosinase. If you want to boil your broccoli, blanch it in boiling water for no more than 20 to 30 seconds, then immerse it in cold water to stop the cooking process.
Adding Mustard Seed Can Maximize Sulforaphane Content Even Further
The sulforaphane content can be further optimized by adding a myrosinase-containing food to it. As reported by the American Institute for Cancer Research (AICR):28
"[P]articipants ate a broccoli supplement with no active myrosinase. When some participants ate a second food with myrosinase, their blood and urine levels of sulforaphane were significantly higher than those who did not eat the food."
Foods containing this important enzyme include:
- Mustard seed
- Daikon radishes
- Cole slaw
A 2013 study that focused on mustard seed — which is said to contain a particularly resilient form of myrosinase — confirmed that mustard seed can boost sulforaphane formation even in boiled broccoli. As noted by the authors:29
"Boiling broccoli in water prevented the formation of any significant levels of sulforaphane due to inactivated myrosinase. However, addition of powdered mustard seeds to the heat processed broccoli significantly increased the formation of sulforaphane."
Adding a myrosinase-rich food is particularly important if you do not steam or flash-blanche raw broccoli. For example, frozen broccoli typically has a reduced amount of myrosinase as it's already been blanched as part of the processing. Boiling or microwaving it further can easily lead to it being more or less devoid of sulforaphane. So if you're using frozen broccoli, be sure to add a food that contains myrosinase (see list above).
Some Broccoli Each Day May Keep the Doctor Away
The benefits of broccoli are remarkable indeed, making it well worth your effort to add a few broccoli spears and/or broccoli sprouts to your meals on a regular basis. Doing so has been shown to:30
✓ Support detoxification, thanks to the phytonutrients glucoraphanin, gluconasturtiian and glucobrassicin
✓ Reduce inflammation, which is at the root of many chronic diseases
✓ Fight allergies, thanks to the flavonoid kaempferol
✓ Improve digestion and gut health, courtesy of significant amounts of fiber
✓ Support eye health, thanks to high levels of the carotenoids lutein and zeaxanthin
✓ Benefit your skin, as sulforaphane helps repair skin damage
✓ Provide important vitamins and minerals, including magnesium, potassium, calcium, protein and vitamin C
✓ Help reduce blood sugar levels, as it contains both soluble fiber and chromium
✓ Support heart health help prevent thickening of your arteries